CN107495815B

CN107495815B - Control line clamp and wire loop system and method

Info

Publication number: CN107495815B
Application number: CN201710444423.6A
Authority: CN
Inventors: 维克多·雨果·奥西格达·盖拉戈; 吕双义
Original assignee: Polygroup Macau Ltd BVI
Current assignee: Polygroup Macau Ltd BVI
Priority date: 2016-06-14
Filing date: 2017-06-13
Publication date: 2021-01-08
Anticipated expiration: 2037-06-13
Also published as: CN107495815A; US20170358550A1; CA2970322A1; DK3517791T3; MX2017007837A; US10622328B2; EP3260022B1; EP3517791B1; EP3260022A1; DK3260022T3; EP3517791A1

Abstract

The present invention includes a control line clamp for securing a control component, such as a control line, in place. The default state of the control line clamp is the clamped state. A force may be applied to the clamp handle to place the control line clamp in a non-clamping state.

Description

Control line clamp and wire loop system and method

Cross-referencing of priorities

In accordance with the provisions of clause 119(e) of the U.S. code 35, the present invention is claimed to be entitled U.S. provisional application No.62/349,853 entitled "control line clamp system and method" filed on 2016, 6, 14, the entire contents and substance of which are incorporated herein by reference in their entirety, all as follows.

Technical Field

The present invention relates to a clamping device for securing a control line, and more particularly, for securing a control line for bringing hinged branches of an artificial christmas tree into a stowed state.

Background

Clamps are well known securing devices that can be used to hold or secure an object firmly in place by applying inward pressure on both clamping surfaces. However, existing clamp designs may not be suitable for adjustably securing controls (e.g., a length of wire, a strap, a rope, a wire, a cord, etc.) for changing branch components to a stowed state in an artificial tree device. It is desirable to connect such control means to a plurality of branches such that the control means forms a wire loop around the trunk of the artificial tree device. It may also be desirable to utilize a clamp device to change and maintain the plurality of branches in either a stowed position (e.g., the branches are substantially parallel to the trunk of the artificial tree) or a deployed position (e.g., the branches are substantially perpendicular to the trunk of the artificial tree). In some embodiments, the control member may form a closed loop of wire, and the gripping device may contact the control member at two or more locations along the control member, thereby forming a larger loop of wire around the tree device and a smaller loop of wire formed on a side of the gripping structure opposite the tree device. The smaller loops may be pulled or otherwise adjusted to transition the limb to the stowed position, which will reduce the diameter of the larger loop of wire, forcing the limb from the deployed state to the stowed state. This will reduce the volume of the tree and make it easier to store.

In some embodiments, the control component may be an open loop (e.g., the control loop has two unconnected ends), however, the control component may be connected to a plurality of branches such that it may substantially encircle the trunk of the artificial tree device, which would form the loop portion of the control component. The loop portion may be adjusted to the stowed position by pulling or otherwise adjusting the control member away from the ends of the artificial tree device and tightening the control member with a clamp device to maintain the currently reduced diameter of the loop. The wire loop may be adjusted to the deployed position by pulling a portion of the wire loop away from the clamp device and tightening the control member with the clamp device to maintain the increased diameter of the wire loop.

Current clip designs are not sufficient to properly secure control components to maintain their stowed or deployed positions, and/or are complex or difficult to use when tension or slack forces develop in the wire loops connected to the control components of the plurality of tree branches. In particular, it is difficult to release the clamping force or loosen the control member, and it is also difficult to apply a clamping or other gripping force to the control member. Furthermore, in one-handed use, it is difficult to clamp or loosen the control component by the existing clamp device, since it requires the use of the other hand to move the control component relative to the clamp device. Accordingly, there is a need for a system that adjustably secures a control component for adjusting the size of a control wire loop. There is also a need for a system that can be easily adjusted between a clamped position and an undamped position. Further, there is a need for a system that can be easily adjusted between a clamped position and an undamped position using a single hand.

Disclosure of Invention

In order to overcome the problems of the prior art, the present invention provides a clamping device, comprising:

a base having a first end and a second end;

a handle having a first end and a second end; and

a spring, wherein a bottom portion of the spring is coupled to the base and a top portion of the spring is coupled to the handle, the spring configured to apply a force to the second end of the handle to move the second end of the handle away from the base such that a front end of the handle applies a force directly to a front end of the base.

The present invention also provides an artificial tree connection system, comprising:

a trunk portion of an artificial tree comprising a plurality of branches hingedly connected to the trunk portion, wherein at least one of the plurality of branches comprises an aperture;

a control wire passing through said at least one hole to form a tree wire loop; and

a clamp structure, comprising:

a base having first and second slots extending from a first end of the base to a second end of the base;

a handle rotatably coupled to the base, the handle having a first end and a second end;

a compression spring disposed to apply a force to the second end of the handle and the second end of the base, thereby biasing the first end of the handle toward the first end of the base;

wherein a first portion of the control line passes through the first slot and a second portion of the control line passes through the second slot.

Drawings

Reference will now be made to the accompanying drawings, which are not necessarily shown to scale, and wherein:

FIG. 1 shows a perspective view of a control line clamp, according to an exemplary embodiment of the present invention.

FIG. 2 illustrates an exploded view of a control line clamp, according to an exemplary embodiment of the present invention.

FIG. 3A shows a cross-sectional side view of a control line clamp with a control component in a clamped state, according to an exemplary embodiment of the invention.

FIG. 3B shows a cross-sectional side view of a control line clamp with a control component in a non-clamped state, according to an exemplary embodiment of the invention.

FIG. 4A shows a perspective view of a control line clamp and control components used on an artificial tree in a stowed position, according to an exemplary embodiment of the present invention.

FIG. 4B shows an enlarged partial view of a control line clamp used on an artificial tree in a stowed position, according to an exemplary embodiment of the present invention.

FIG. 5A illustrates a perspective view of a control line clamp and control components used on an artificial tree in a deployed position, according to an exemplary embodiment of the invention.

FIG. 5B shows an enlarged partial view of a control line clamp used on an artificial tree in a deployed position, according to an exemplary embodiment of the invention.

Detailed Description

The present invention may be better understood by reference to the following detailed description of embodiments and examples. Before describing embodiments of the apparatus and method of the present invention, it is to be understood that the embodiments are not intended to limit the invention. Many modifications and variations therein will be apparent to those skilled in the art and are still within the scope of the invention. It is also to be understood that the terminology used herein is for the purpose of describing particular embodiments only and is not intended to be limiting. Some embodiments of the invention will be described more fully hereinafter with reference to the accompanying drawings. This invention may, however, be embodied in many different forms and should not be construed as limited to the embodiments set forth herein.

Numerous specific details are set forth below. However, it is understood that embodiments of the invention may be practiced without these specific details. In other instances, well-known methods, structures and techniques have not been shown in detail in order not to obscure the understanding of this description. The use of "an embodiment," "one embodiment," "an example embodiment," "some embodiments," "certain embodiments," "various embodiments," etc., indicate that an embodiment of the invention may include a particular feature, structure, or characteristic, but not all embodiments need necessarily include the particular feature, structure, or characteristic. Moreover, repeated use of "in an embodiment" does not necessarily refer to the same embodiment, although it may.

Unless otherwise indicated, the terms used herein should be understood as commonly used by one of ordinary skill in the relevant art. Unless a definition of terms is given below, it should be understood that the terms "a" and "an" as used in the specification and claims may mean one or more, depending on the context in which they are used. Throughout the specification and claims, the following terms take at least the meanings explicitly associated herein, unless the context clearly dictates otherwise. The term "or" is intended to mean including "or". Furthermore, the terms "a," "an," and "the" are intended to mean one or more, unless specifically indicated otherwise or clear from context to be directed to a singular form.

Unless otherwise specified the use of the adjectives "first", "second", "third", etc., to describe a common object, merely indicate that different instances of like objects are being described, and are not intended to imply that the objects so described must be in a given sequence, either temporally, spatially, in ranking, or otherwise.

Also, in the embodiments, terms are used for clarity of description. It is intended that each term take the broadest meaning as understood by those skilled in the art and include all technical equivalents which operate in a similar manner to accomplish a similar purpose.

To facilitate an understanding of the principles and features of embodiments of the present invention, exemplary embodiments are described below with reference to implementations of the exemplary embodiments. However, such illustrative embodiments are not intended to be limiting.

The materials described hereinafter as constituting the various elements of the embodiments of the invention are intended to be illustrative and not limiting. Many suitable materials that perform the same or similar function as the materials described herein are included within the scope of the embodiments. Such other materials not described herein may include, but are not limited to, materials such as those developed after the development of the present invention.

Embodiments of the present invention include a control line clamp for securing a control component in place. In various embodiments, the control line clamp may be used to adjustably secure a control member that is configured to be tightened around the artificial christmas tree to urge the branches of the artificial tree upward into a stowed position for storage. Such trees and control components are disclosed in U.S. patent No.9,101,173, the contents of which are incorporated herein by reference. In some embodiments, the control line clamp may have two states: a clamped state and an unclamped state. In the clamped state, the spring may provide a force to the control line clamp which in turn exerts a clamping force on the control member, securing the control member in place. In this undamped state, a user can apply a force on the clamp handle to compress the spring, which can release the clamping force on the control member, pulling the control member forward or backward through the slot of the body of the control wire clamp. According to some embodiments, the control line clamp may default to a clamped state.

It should be understood that the control component may include a first portion (i.e., a wire loop) that is looped around the tree and then fed through the control wire clamp to provide a second portion for user engagement. The second portion may be a second smaller loop of wire or an unconnected first or second wire end. When the control line clamp is in the undamped state, the user can pull the second portion through the control line clamp and away from the tree so that it can tighten the first portion (i.e., the control wire loop) around the artificial tree. As described above, in some embodiments, the first portion of the control component may form a control wire loop around a plurality of branches, in contact with a lower portion of each branch. Tightening the control member (i.e., pulling the second portion through the control line clamp and away from the tree) forces the branches, which were initially in a generally horizontal state, to rotate to a generally vertical state. The branches may be connected to the trunk of the artificial christmas tree by hinges so that when the control unit is tightened, the branches rotate from the extended position to the stowed position. When the branches are in the desired convenient location for storage, the user can clamp or secure the control means by releasing the force on the clamp handle (i.e. returning the control line clamp to the clamped state) so that the branches of the artificial tree can be maintained in a generally upright position for storage.

In the present invention, certain embodiments are illustrated by way of example in relation to a tensioned control member for securing an artificial Christmas tree. However, the embodiments of the present invention are not limited thereto. In some embodiments, the present invention may effectively secure a control component that includes, for example, one or two lines or line segments that may be used to control and/or secure other objects.

Referring now to the drawings, FIGS. 1 and 2 illustrate an embodiment of a control line clamp 100. As described above, the control line clamp 100 may be used to secure the control component 118 in place when the control line clamp 100 is in the clamped state. The control component 118 may generally have a first portion on a first side of the control line clamp 100 (e.g., the portion of the control component 118 that surrounds the branches of a christmas tree) and a second portion on a second side of the control line clamp 100 (e.g., the portion of the control component 118 that is accessible to a user to tighten or loosen the first portion of the control component 118). The amount of the portion of the control member 118 located on the first or second side of the control line clamp 100 can be adjusted by pulling the control member 118 forward or backward. As such, when in the undamped state, the control line clamp 100 can pull the control component 118 forward or backward through the body of the control line clamp 100. Thus, when the control line clamp 100 is in the undamped state, the control member 118 can be adjusted to a desired length, position, or tightness, and then the control member 118 can be securely fixed in the desired position by returning the control line clamp 100 to the clamped state. According to some embodiments, the control member 118 may be an elastic rod, a wire, a string, a rubber band, an elastic material, or any other material that may form a wire loop with an adjustable diameter. In some embodiments, control component 118 may have a control component pull tab 120 at one end that provides a surface for a user to grasp in order to more easily pull control component 118 away from control line clamp 100 (e.g., tighten the wire loop on the opposite side of control line clamp 100).

Although the present invention is directed to a control component 118 wherein the first portion forms a wire loop such that the control component 118 passes through the clamp base 102 at two locations (i.e., the two

segments

118a and 118b of the control component 118 pass through the control wire clamp 100, as shown in fig. 1 and 2), it should be understood that: in some embodiments, the portion of the control component 118 on the second side of the control wire clamp 100 may not form a wire loop. Thus, in some embodiments, the control line clamp 100 may receive a single control component 118 segment (e.g., a segment of line rather than two segments of line (e.g., 118a and 118 b)).

In some embodiments, the control line clamp 100 may include a clamp base 102, a clamp handle 106, and a spring 116. The clamp handle 106 may have a rear end 108. According to some embodiments, a user may press down on the rear end 108 of the clamp handle 106 to place the control line clamp 100 in a non-clamping state. When the clamp handle 106 is released, the control line clamp 100 may automatically return to the clamped state.

In some embodiments, the transition from the undamped state to the clamped state may be driven by the spring force provided by the spring 116. In some embodiments, the clamp base 102 may include a spring retaining element that may secure the bottom of the spring 116 to the clamp base 102. In some embodiments, the spring retaining element may be a circular protrusion extending outwardly from the surface of the clamp base 102 so that the bottom portion of the spring may fit snugly around the circular protrusion. In some embodiments, the spring retaining element may be, for example, one or more pins, adhesives, pins, or other suitable devices that effectively secure the bottom portion of the spring 116 to the clamp base 102. In some embodiments, a top portion of the spring 116 may contact a lower portion of the clamp handle 106. Thus, in some embodiments, the spring 116 may be securely contained between a lower portion of the clamp handle 106 and a surface of the clamp base 102. Thus, in some embodiments, when a downward force is applied to the rear end 108 of the clamp handle 106 (e.g., by a user pressing down on the rear end 108 of the clamp handle 106), the force may force the clamp handle 106 downward into the spring 116, compressing the spring 116. When the force on the rear end 108 of the clamp handle 106 is released (e.g., by the user releasing the clamp handle 106), the spring force of the spring 116 may cause the rear end 108 of the clamp handle 106 to move upward and away from the clamp base 102.

According to some embodiments, the front end 109 of the clamp handle 106 is rotatably coupled to the clamp base 102. In some embodiments, one or both sides of the front end 109 of the clamp handle 106 or thereabout and one or both sides of the corresponding clamp base 102 may include apertures aligned with one another such that a bolt 112 may be passed through the apertures of the clamp handle 106 and clamp base 102 to rotatably couple the clamp handle 106 with the clamp base 102. Thus, in some embodiments, the clamp handle 106 may rotate about the bolt 112. The bolt 112 may be secured by, for example, a nut 114. Other embodiments may be other arrangements that rotate at or near the front end 109. For example, some embodiments may include a rounded protrusion on the clamp handle 106 that is configured to mate with a recess on the clamp base 102 (or vice versa). It should be understood by those skilled in the art that other structures are also contemplated herein that would allow the clamp handle 106 to be rotatably coupled to the clamp base 102.

As shown in fig. 2, in some embodiments, the clamp base 102 may include two base slots 104 that may receive a portion of the control component 118. The base slot 104 can laterally secure the control component 118 within the clamp base 102. In some embodiments, the base slot 104 may be located below the front end 109 of the clamp handle 106. The base slot 104 may extend through the clamp base 102 throughout the length of the base slot and is configured to receive the control member 118 at a first end such that the control member 118 extends through the length of the base slot 104 and protrudes from an opposite end. In some embodiments, the base slot 104 may include a recess 111 in the body of the clamp base 102. As shown in FIG. 1, in some embodiments, the base slots 104 may each include a curved or serrated recess 111. The curved or serrated edges of each recess 111 serve to provide a surface for generating frictional forces that act on the control member 118 if the control member 118 is pulled forward or backward away from the clamp base 102.

Fig. 3A shows the control line clamp 100 in a clamped state and fig. 3B shows the control line clamp 100 in an undamped state. As indicated above, the clamp handle 106 is rotatably coupled to the clamp base 102. In some embodiments, the front end 109 of the clamp handle 106 may include one or more raised edges 110. The front end may have a generally circular cross-section from which the raised edge 110 may extend. In some embodiments, the raised edge 110 can be disposed in close proximity (i.e., closer than other portions of the front end 109) to a recess 111 of the clamp base 102, which can be used to secure a control component 118 when the control line clamp 100 is in a clamped state. In some embodiments, as shown in fig. 3A, the protruding edge 110 may extend outward from the main body of the clamp handle 106 in a manner that: when the control line clamp 100 is in the clamped state, the protruding edge 110 of the front end 109 of the clamp handle 106 can extend downward into the base slot 104 and into contact with the control member 118. As can be seen in FIG. 3A, the raised edge 110 exerts a downward force on the control member 118, thereby securing (or connecting) the control member 118 to the clamp base 102 and preventing the control member 118 from being pulled forward or backward. As described above, the spring force of the spring 116 serves to apply an upward force to the rear end 108 of the clamp handle 106, which is converted into a rotational force rotating about the fulcrum of the control phase clamp 100 (i.e., about the bolt 112) to pull the projecting edge 110 into the base groove 104. As shown in FIG. 3B, when a downward force is applied to the rear end 108 of the clamp handle 106, the force rotates the front end 109 of the clamp handle 106 to move the projecting edge 110 away from the recess 111 of the base slot 104, thereby releasing the force on the control member 118 secured between the projecting edge 110 of the front end 109 of the clamp handle 106 and the recess 111 of the slot 104 of the clamp base 102. Thus, once the control member 118 is released, the released control member 118 can be pulled in either a forward or rearward direction over the base slot 104.

Fig. 4A, 4B, 5A and 5B show views of control line clamp 100 in use on an artificial tree. Fig. 5A and 5B show the control line clamp 100 in a clamped state with the branches of the artificial tree in an extended state. As shown in fig. 5B, only a small portion of the control component 118 is positioned in front of the control line clamp 100 (i.e., in the second position). Fig. 4A and 4B show views of the control phase spacing 100 in a clamped state and the artificial tree in a stowed position. To rotate from the position shown in fig. 4A to the position shown in fig. 5A (or vice versa), the control line clamp 100 may be set in an undamped state, the control member 118 may be pulled forward or reverse to tighten or loosen the wire loop around the branch, and the control line clamp 100 may be returned to a clamped position to secure the branch along the trunk of the artificial tree. As shown in fig. 4B and 5B, the portion of the control component 118 in fig. 4B (i.e., when the tree is in the stowed position) that is in front of the control line clamp 100 is significantly larger than in fig. 5B (i.e., when the tree is in the deployed position). In addition, in contrast to the position shown in FIG. 5A, it can be seen from FIG. 4A that the branches have been pressed into a generally upright position (i.e., generally parallel to the trunk of the artificial tree) by the control unit 118 so that the artificial Christmas tree can be easily stored.

While certain embodiments of the invention have been described in connection with what is presently considered to be the most practical and preferred embodiment, it is to be understood that the invention is not to be limited to the disclosed embodiments, but on the contrary, is intended to cover various modifications and equivalent arrangements included within the scope of the appended claims. Although specific terms are employed herein, they are used in a generic and descriptive sense only and not for purposes of limitation.

This written description uses examples to illustrate certain embodiments of the invention, including the best mode, and also to enable any person skilled in the art to practice certain embodiments of the invention, including making and using any devices or systems and performing any incorporated methods. The patentable scope of certain embodiments of the invention is defined in the claims, and includes other embodiments that occur to those skilled in the art. Such other ways are included in the scope of the claims if they have structural elements that do not differ from the literal language of the claims, or if they include equivalent structural elements with insubstantial differences from the literal languages of the claims.

Claims

1. A clamp device, comprising:

a handle having a first end and a second end, the handle comprising a first protrusion and a second protrusion, the first protrusion and the second protrusion each having an outer surface;

a base having a first end and a second end, the base comprising

A first slot extending in a length direction of the base and configured to receive a first portion of a control wire and at least a portion of a first projection of the handle, the first slot including a first pair of opposing sidewalls extending from a first end to a second end of the base;

a first recess disposed in the first slot between the first pair of opposing sidewalls, the first recess disposed in alignment with at least a portion of the first protrusion;

a second slot extending in a length direction of the base and configured to receive a second portion of the control cord and at least a portion of the second projection of the handle, the second slot including a second pair of opposing sidewalls extending from the first end to the second end of the base; and

a second recess disposed in the second slot between the second pair of opposing sidewalls, the second recess disposed in alignment with at least a portion of the second protrusion;

a spring, wherein a bottom portion of the spring is coupled to the base and a top portion of the spring is coupled to the handle, the spring configured to apply a force to the second end of the handle to move the second end of the handle away from the second end of the base such that the first end of the handle applies a force directly to the first end of the base;

wherein the first and second protrusions are configured to press the first and second portions of the control wire into the first and second recesses, respectively, as the spring transitions from the compressed position to the extended position; and

the spring is configured to transition from the extended position to the compressed position as the second end of the handle moves toward the second end of the base, the transition causing the first and second protrusions to move away from the first and second recesses, thereby causing the first and second portions of the control wire to be released from the first and second recesses, respectively.

2. The clamp device recited in claim 1, wherein: also included is a control wire having a first portion and a second portion, a front wire loop extending from the first end of the base and a rear wire loop extending from the second portion of the base when the first portion of the control wire is in the first slot and the second portion of the control wire is in the second slot.

3. The clamp device recited in claim 1, wherein: the bottom portion of the spring is connected near the second end of the base and the top portion of the spring is connected near the second end of the handle.

4. The clamp device recited in claim 1, wherein: and a bolt and a nut, wherein the handle is rotatably connected to the base through the bolt and the nut.

5. The clamp device recited in claim 1, wherein: the first protrusion is a first circular protrusion, the second protrusion is a second circular protrusion, and the first recess of the base includes a first recess configured to receive the first circular protrusion, and the second recess of the base includes a second recess configured to receive the second circular protrusion.

6. A clamp system, comprising:

a base having a first end and a second end, the base including a first groove and a second groove each extending from the first end of the base to the second end of the base, each groove including a pair of opposing sidewalls, at least a portion of each sidewall having an undulating profile, the first groove including a first recess and the second groove including a second recess;

a handle rotatably coupled to the base, the handle having a first end including a raised edge, the raised edge including a first projection configured to extend into a first slot and a second projection extending into a second slot;

a control wire loop having a first portion extending through the first slot and a second portion extending through the second slot; and

a spring configured to apply a force to the second end of the base and the second end of the handle such that the first end of the base is forced toward the first end of the handle such that at least a portion of the control wire loop is sandwiched between the first end of the base and the first end of the handle;

wherein, when the spring is in the extended position, the first and second protrusions press the first and second portions of the control wire into the first and second recesses, respectively; and

7. The clamp system of claim 6, wherein: a front wire loop extends from the first and second slots at a first end of the base and a rear wire loop extends from the first and second slots at a second end of the base.

8. The clamp system of claim 7, wherein: a pull tab is also included that is connected to the front wire loop.

9. The clamp system of claim 8, wherein: the posterior loop is formed by a plurality of coils, each coil being connected to a branch of an artificial tree.

10. An artificial tree connection system, comprising:

a control wire passing through at least one of said holes to form a tree wire loop; and

a clamp structure, comprising:

a base having a first slot and a second slot extending from a first end of the base to a second end of the base, wherein each slot includes a pair of opposing sidewalls, at least a portion of each sidewall having a saw-tooth profile, the first slot including a first recess and the second slot including a second recess;

a handle rotatably coupled to the base, the handle having a first end and a second end, the first end including a first protrusion configured to extend into the first slot and a second protrusion configured to extend into the second slot;

wherein a first portion of the control line passes through the first slot and a second portion of the control line passes through the second slot;

the first and second protrusions press the first and second portions of the control wire into the first and second recesses, respectively, when the spring is in the extended position; and

11. The artificial tree connection system of claim 10, wherein: when the tree wire loop is taut, it has a first diameter; and when the tree wire loop is relaxed, it has a second diameter.

12. The artificial tree connection system of claim 11, wherein: when the wire loop has a first diameter, the plurality of branches are substantially parallel to the trunk portion.

13. The artificial tree connection system of claim 10, wherein: the control wire is a loop of control wire such that a pull wire loop extends from the first and second slots at the first end of the base.

14. The artificial tree connection system of claim 13, wherein: and a pull tab connected to the pull wire loop.

15. The clamp device recited in claim 1, wherein: the second groove is separate and distinct from the first groove.

16. The clamp system of claim 6, wherein: the first protrusion is disposed on a first side of the first end portion, and the second protrusion is disposed on a second side of the first end portion, wherein the second side is opposite to the first side, and the second protrusion and the first protrusion are separated and different from each other, and the first protrusion and the second protrusion each have a smooth outer surface.

17. The artificial tree connection system of claim 10, wherein: the first protrusion is disposed on a first side of the first end portion, and the second protrusion is disposed on a second side of the first end portion, wherein the second side is opposite to the first side, and the second protrusion and the first protrusion are separated and different from each other, and the first protrusion and the second protrusion each have a smooth outer surface.